Does Baker's Yeast Really Prevent You From Getting Drunk?

David Kroll
, ContributorOpinions expressed by Forbes Contributors are their own.

This question came to light over a much-ballyhooed excerpt from Aaron Goldfarb'sEsquireinterview with Jim Koch, founder and CEO of Boston Beer Company, makers of the Samuel Adams line of craft lagers and ales.

In the article, "How To Drink All Night Without Getting Drunk," Goldfarb quotes Koch's strategy of pre-treating himself with grocery store-bought, Fleischmann's active dry baker's yeast. Koch claims that one teaspoon of dry yeast per anticipated serving of beer (mixed with yogurt for palatability), "will mitigate – not eliminate – the effects of alcohol." Esquire writers tried to reproduce the effect, admittedly non-scientifically, and pretty much unsuccessfully.

Nevertheless, the April 24th story was cited in several newspapers and magazines, and went viral on social media, with 29,000 Facebook shares, over 1,000 tweets, nearly 400 comments, and an entire Reddit r/beer thread.

Why?

Well, Koch is no humbug in beer circles. Although preceded by Fritz Maytag who resuscitated San Francisco's Anchor Steam Brewing in 1965, Koch (pronounced "cook") is arguably one of the major forces in the resurgence of craft lagers and ales.

So, when Jim Koch speaks, people listen.

Strategy sounds supported by science...at first

Koch's scientific rationale does have a notable pedigree. The idea was developed by the late Ph.D. biochemist, Joseph L. Owades, whose brewing expertise preceded that of Koch and Maytag. Owades is best known for his pre-Miller Lite development of the first light beer and rose to vice president of Brooklyn-based Rheingold, my dad's favorite beer and sponsor of the New York Mets in the 1960s and 1970s.

A few years before passing away in 2005, "Dr. Joe" was granted a U.S. patent (#6,284,244) for the method of prior or concomitant ingestion of baker's yeast as "a process for lowering of blood alcohol (i.e. ethyl alcohol) levels in humans after they imbibe alcoholic beverages such as beer, wine or distilled spirits."

Alcohol dehydrogenase, or ADH, is an enzyme in yeast that produces alcohol. In the brewing process, that's how we get alcohol from the sugars that are released from the malted barley and other grains. But it can also work in the reverse direction to metabolize the alcohol back into its precursor, acetaldehyde. Yeast also have multiple forms of the enzyme the predominate in one direction or another. That's been a little confusing to folks who've been commenting on the topic around the Web.

Owades claims that baker's yeast contains enough ADH to act in the stomach to catalyze that reverse reaction. That conversion of alcohol to acetaldehyde is the theoretical reason why ingesting yeast might lower one's exposure to alcohol.

Where are the data?

Owades' patent application cites experimentation with eight human subjects who quickly ingested various alcoholic beverages with and without the baker's or vintner's yeast pretreatment. He then measured blood alcohol levels for then next three-and-a-half hours afterward using a breath analyzer. In the data presented, Owades claims that the blood levels of ethanol over time were 20-38% lower when subjects ingested yeast at the time of drinking the alcoholic beverage.

Here are the results from two of the eight human subjects Owades tested. A 170 lb. adult man (Fig. 3) and 170 lb. adult woman (Fig. 4) drank 268 mL of chardonnay containing 13% alcohol in 11 minutes - that's slightly less than two glasses of wine - and measured alcohol levels in the breath at various times. The test was then repeated with the subjects drinking the same amount of wine, but only after ingesting 2.5 grams of vintner's yeast, a yeast that can tolerate higher alcohol concentrations. Owades calculated that the yeast lowered overall alcohol by 36% in the man and 21% in the woman. But if you look at any timepoint after the initial peak, there not much of a practical difference in the man and no difference in the woman. Source: U.S. Patent #6,284,244

"My main question is, 'Has anyone ever repeated Owades experiments?,'" asks Robert A. Sclafani, Ph.D., professor of biochemistry and molecular biology graduate program director at the University of Colorado Denver's School of Medicine. Sclafani also leverages his yeast biochemistry expertise as the principal of Brewgenes Consulting Co., a brewing and biotechnology consulting service. (Disclosure: I did my postdoctoral research between 1990 and 1992 in departments at Colorado that were affiliated with Dr. Sclafani's department.)